Long Term Evolution (LTE) networks operate in a number of specific frequency bands and deliver a wide variety of information to an ever-increasing number and type of user equipment (UE). Typically, the use of different communication techniques is limited to licensed bands regulated by the federal government. The growth of network use has sparked an interest in expanding LTE use beyond these licensed bands. LTE-Unlicensed (LTE-U) allows License Assisted Access (LAA) communication devices such as UEs and evolved node Bs (eNBs) to make use of unlicensed spectrum in communications. While only LTE systems are able to legally operate in LTE bands, other systems, such as Wireless Local Area Network (WLAN) systems, coexist with LTE-U systems in the unlicensed spectrum. In particular, WLAN systems using IEEE 802.11a/n/ac technologies have enjoyed widespread use in the 5 GHz Unlicensed National Information Infrastructure (U-NII) bands by both individuals and operators for a variety of purposes.
Typically, unlicensed band users operate on one channel (sub-band) rather than occupying the entire spectrum, making it possible for multiple users to coexist by using different channels. Due to coexistence of communications in the unlicensed band, it would be desirable to determine spectrum usage in the unlicensed band to better provide LAA communications in the unlicensed band.